Speed regulator



Sept. 27, 1932. K. SCHMlDT 1,879,824

SPEED REGULATOR Filed Jan. 5, 1929 Patented Sept. 27, 1932 UNITED STATESPATENT QFFICF KARL SSHMIDT, OF BERLIN-LICI-ITENRADE, GERMANY, ASSGNOR TOC. LORENZ AKTIENGESELLSCEAFT, OF BERLIN-TEMPELHOF, GERMANY SPEEDREGULATOR Application led January 5, 1929, Serial No.

This invention relates to speed regulators and more particularly to aspeed regulating arrangement for maintaining two rotating bodies insynchronism.

An object of the invention is to provide a speed regulator which willmaintain substantially constant the speed of a rotating body which maybe subjected to sudden h-eavy changes in load.

Heretofore it has been proposed to regulate the speed of a motor forsmall variations in load or voltage by means of a pair of contactsrotating with and acting upon the field winding of the motor, whichcontacts operate under action of centrifugal force and gravity to openand close once during each revolution.

According to a feature of the present invention, there is meansresponsive to a difference in speed of two machines particularly whenthe machine to be regulated is subjected to a sudden heavy load acts tospace contacts whose opening and closure once during each revolution ofthe controlling machine under the action of centrifugal force andgravity. Thus, the unresponsiveness of machines controlled by suchregulators to sudden load or voltage fluctuations can be utilized, andat the same time proper correction made for small changes in the machinespeeds, which, although often imineasurably small, must always existwith fluctuations of that kind.

ln the accompanying drawing Figs. 1, 2 and 3 are diagrammaticperspective views, partly in section, showing a corresponding number ofconstructional forms of the invention by way of example. The samereference characters in the views refer to constructional or circuitelements of the same kind.

In the arrangement according to Fig. 1, direct current supply leads 1, 2are connected to a. direct current driving motor 3, the speed of whichis to be keptsynchronous with that of a control motor 4. On the shaft 5of the motor 8 is a disc 7 arranged in parallel to another disc 8 on theshaft 6 of the motor 4. Between the discs and 8 rotate two frictionwheels 9 and 10 which are mounted on a shaft 11, so located that thewheels touch the disc 330,681, and in Germany January 17, 1928.

.7 but not 8. This shaft 11 is pivoted in two bearings 12 and 13. On theupper end of the shaft 11 is a thread which shifts a contact 15 whenshaft 11 is driven. A movable contact 14 is mounted upon the free end ofa plate .a

manner on each revolution of the disc 8. (See my U. S. Patent1,647,020.) Said resistance 16 is located in series with anotherresistance 17 in the field windings 18 of the motor S so as to beentirely or partly iniuenced by the regulating arrangements described asabove. The rotary windings of motor 3 are connected with the slip rings19 on the motor sha-ft and direct supplied by 1 and 2.

lf the auxiliary machine 4 has a fixed nonvarying speed then, so long asthe motor 8 likewise keeps to this speed, the discs 7 and 8 will remainrelative to one another in quietude. If the motor 4, on the other hand,runs faster or slower than its predetermined speed, then friction wheels9, 10 will be rotated by the disc 7 and change the distance apart of thecontacts, and thus the mean opening and closing time ofthe contacts 14and 15. In this way the motor receives an additional torque, by varyingthe field tension through the closed resistance 1G, which acts -inopposition to the difference of movement, so that the exact synchronouscondition is continually maintained.

The saine synchronizing action on the speed of the motor can also beproduced by variation of the range of regulation, not by changing thedistances of the contacts 14 and 15 as described above, but by varyingan additional field resistance in the way of a rough regulation, asshown in Fig. 2, so that here also a speed of the motor 3 absolutelysynchronous with that of the motor 4 will be maintained.

In the construe-tional example according to Fig. 2 a variable resistance21, 22 located in the field current circuit is varied by relativemovements of the wheels 9 and 10. The resistance member 21 is herewithconnected across slip rings 23 electrically connected with thefield-supply 16, 18 of the motor 3. By this means synchronism is alwaysproduced while the fast regulator guarantees non-sensitivity to load andvoltage fluctuations. l

The construction according to Fig. 3 differs from Fig. 1 in making thecontrolling action directly dependent upon the mean opening and closingtime of the contacts. This can be done, for example, by means of'a smallreversible' direct current motor 30, which works a rough-regulation inthe form of an additional resistance 32 (similar to 21 in Fig. 2). Thereversing of the motor is effected by means of the relay 26, which,under the infin# ence of the mean contact current and t-he inechanicalforce of a spring 35', closes the armature 27 on the one or the otherpole of the battery 33 by contacts 28, 29, whilst the field 31 of motor30 is always excited in the same direction. Other means may be used forvarying the resistance 16 in Fig. 3 Such as simple relays, diEerent-ialrelays and the'like, either alone or in connection with auxiliarymotors. Likewise instead of the friction discs and friction wheelsVmentioned in all the constructional examples, correspondinglyconstructed ring gears and pinions may be used;

What I claim is 1. Means for maintaining two rotary electrical devicesin synchronism comprising a disc rotated by each device, a pair ofcontacts carried by one of the discs and adapted Vto open and closeduring each revolution, a field winding for the device which rotates theother disc and influenced by the opening and closing of said contacts,and a rotary member carried by the contact carrying disc and engagingthe other disc and rotated thereby whenever there is a diference inspeed of said discs to vary the relative spacing of said contacts.

2. Means for maintaining two rotary electrical devices in synchronismaccording to claim 1, wherein a resistance in circuit with the eldwinding is short-circuited by-the closing of said contacts.

3. Means for maintaining two rotary elec'- tri'cal devices insynchronism according to claim 1 wherein a resistance is in circuit withthe field winding, and means responsive to the `opening or closure ofsaid contacts for varying said resistance.

In testimony whereof I have aiiixed my signature.

KARL SCHMIDT.

